Minnesota

Archaeologists are scanning the bottom of one of Minnesota's largest lakes for unknown shipwrecks, and have already found some.

A renewed effort to see what's lurking at the bottom of Lake Minnetonka has uncovered three historically significant shipwrecks from when the lake was a popular tourist attraction at the turn of the 20th century.

Tempted to don a diving suit and seek out a treasure chest ?

You'd come up empty-handed, because these wrecks and others, mostly steamboats, ferries or barges, were stripped clean of anything valuable and some were intentionally sunk when they became outdated.

"Artifacts for us are the fittings on the boats, the different cleats, the wheels if they're left on," said Ann Merriman of Maritime Heritage Minnesota, which found the remains during a sonar survey that also turned up several dozen smaller images that may be rowboats, cars or other long-lost items.

Seeing how the boats were crafted and used is historically important and their locations will be mapped so that they can be recognized as state archaeological sites. That would help keep them safe from disruption and allow divers to explore their wreckage.

"Our goal is to keep wrecks safe from looting, and safe from damage from anchors, but it's certainly not to limit scuba divers' enjoyment of them," Merriman said.

Merriman and her husband, Chris Olson, trolled the eastern, or lower half, of the large lake last fall and took hundreds of sonar images. The couple will survey the other half of Lake Minnetonka next month, looking for more.